KNOWPIA
WELCOME TO KNOWPIA
Isotopes of magnesium 
Summary
Magnesium (12Mg) naturally occurs in three stable isotopes, 24Mg, 25Mg, and 26Mg. There are 19 radioisotopes that have been discovered, ranging from 18Mg to 40Mg. The longest-lived radioisotope is 28Mg with a half-life of 20.915 hours. The lighter isotopes mostly decay to isotopes of sodium while the heavier isotopes decay to isotopes of aluminium. The shortest-lived is proton-unbound 19Mg with a half-life of 5 picoseconds, though the half-life of similarly unbound 18Mg has not been measured.
| ||||||||||||||||||||||||||||||
| Standard atomic weight Ar°(Mg) | ||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
The abundances of the naturally occurring isotopes of magnesium.
List of isotopesEdit
| Nuclide[3] |
Z | N | Isotopic mass (Da)[4] [n 1] |
Half-life [n 2] |
Decay mode [n 3] |
Daughter isotope [n 4] |
Spin and parity [n 5][n 2] |
Natural abundance (mole fraction) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Normal proportion | Range of variation | ||||||||||||||||||
| 18Mg[5] | 12 | 6 | 2p | 16Ne | 0+ | ||||||||||||||
| 19Mg | 12 | 7 | 19.03417(5) | 5(3) ps | 2p | 17Ne | 1/2−# | ||||||||||||
| 20Mg | 12 | 8 | 20.0187631(2) | 93(5) ms | β+ (69.7%) | 20Na | 0+ | ||||||||||||
| β+, p (30.3%) | 19Ne | ||||||||||||||||||
| 21Mg | 12 | 9 | 21.0117058(8) | 118.6(5) ms | β+ (66.9%) | 21Na | 5/2+ | ||||||||||||
| β+, p (32.6%) | 20Ne | ||||||||||||||||||
| β+, α (0.5%) | 17F | ||||||||||||||||||
| 22Mg | 12 | 10 | 21.9995707(3) | 3.8755(12) s | β+ | 22Na | 0+ | ||||||||||||
| 23Mg | 12 | 11 | 22.99412394(17) | 11.317(11) s | β+ | 23Na | 3/2+ | ||||||||||||
| 24Mg | 12 | 12 | 23.985041697(14) | Stable | 0+ | 0.7899(4) | 0.78958–0.79017 | ||||||||||||
| 25Mg | 12 | 13 | 24.98583696(5) | Stable | 5/2+ | 0.1000(1) | 0.09996–0.10012 | ||||||||||||
| 26Mg[n 6] | 12 | 14 | 25.98259297(3) | Stable | 0+ | 0.1101(3) | 0.10987–0.11030 | ||||||||||||
| 27Mg | 12 | 15 | 26.98434063(5) | 9.435(27) min | β− | 27Al | 1/2+ | ||||||||||||
| 28Mg | 12 | 16 | 27.9838766(21) | 20.915(9) h | β− | 28Al | 0+ | ||||||||||||
| 29Mg | 12 | 17 | 28.988617(12) | 1.30(12) s | β− | 29Al | 3/2+ | ||||||||||||
| 30Mg | 12 | 18 | 29.990463(4) | 313(4) ms | β− (99.94%) | 30Al | 0+ | ||||||||||||
| β−, n (0.06%) | 29Al | ||||||||||||||||||
| 31Mg | 12 | 19 | 30.996648(3) | 236(20) ms | β− (93.8%) | 31Al | 1/2(+) | ||||||||||||
| β−, n (6.2%) | 30Al | ||||||||||||||||||
| 32Mg | 12 | 20 | 31.999110(4) | 86(5) ms | β− (94.5%) | 32Al | 0+ | ||||||||||||
| β−, n (5.5%) | 31Al | ||||||||||||||||||
| 33Mg | 12 | 21 | 33.005327(3) | 90.5(16) ms | β− (86%) | 33Al | 3/2− | ||||||||||||
| β−, n (14%) | 32Al | ||||||||||||||||||
| 34Mg | 12 | 22 | 34.00894(3) | 20(10) ms | β− (70%) | 34Al | 0+ | ||||||||||||
| β−, n (30%) | 33Al | ||||||||||||||||||
| 35Mg | 12 | 23 | 35.01679(29) | 70(40) ms | β−, n (52%) | 34Al | 7/2−# | ||||||||||||
| β− (48%) | 35Al | ||||||||||||||||||
| 36Mg | 12 | 24 | 36.02188(74) | 3.9(13) ms | β− | 36Al | 0+ | ||||||||||||
| 37Mg | 12 | 25 | 37.03029(75) | 8(4) ms | β− | 37Al | (3/2−) | ||||||||||||
| β−, n | 36Al | ||||||||||||||||||
| 38Mg | 12 | 26 | 38.03658(54)# | 1# ms [>260 ns] | 0+ | ||||||||||||||
| 40Mg | 12 | 28 | 40.05191(54)# | 1# ms | β−, n | 39Al | 0+ | ||||||||||||
| β− | 40Al | ||||||||||||||||||
| This table header & footer: | |||||||||||||||||||
- ^ ( ) – Uncertainty (1σ) is given in concise form in parentheses after the corresponding last digits.
- ^ a b # – Values marked # are not purely derived from experimental data, but at least partly from trends of neighboring nuclides (TNN).
- ^
Modes of decay:
n: Neutron emission p: Proton emission - ^ Bold symbol as daughter – Daughter product is stable.
- ^ ( ) spin value – Indicates spin with weak assignment arguments.
- ^ Used in radiodating events early in the Solar System's history
External linksEdit
- Magnesium isotopes data from The Berkeley Laboratory Isotopes Project's
ReferencesEdit
- ^ "Standard Atomic Weights: Magnesium". CIAAW. 2011.
- ^ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
- ^ Half-life, decay mode, nuclear spin, and isotopic composition is sourced in:
Audi, G.; Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S. (2017). "The NUBASE2016 evaluation of nuclear properties" (PDF). Chinese Physics C. 41 (3): 030001. Bibcode:2017ChPhC..41c0001A. doi:10.1088/1674-1137/41/3/030001. - ^ Wang, M.; Audi, G.; Kondev, F. G.; Huang, W. J.; Naimi, S.; Xu, X. (2017). "The AME2016 atomic mass evaluation (II). Tables, graphs, and references" (PDF). Chinese Physics C. 41 (3): 030003-1–030003-442. doi:10.1088/1674-1137/41/3/030003.
- ^ Jin, Y.; et al. (2021). "First observation of the four-proton unbound nucleus 18Mg". Physical Review Letters. 127 (262502). doi:10.1103/PhysRevLett.127.262502.